An experimental study of the Timoshenko's shear coefficient for flexurally vibrating beams

The validity of the shear coefficient K has been experimentally tested using a large number of rectangular glass beams and cylindrical phosphor-bronze beams. The theoretical expressions of K=(5+5m)/(6+5m) for rectangular beams and K=(6+12m+6m2)/(7+12m+4m2) for cylindrical beams, where m is Poisson's ratio, have been confirmed to yield the best agreement with experiment. For cylindrical beams, Timoshenko's theory has been shown to give good results over a fairly wide frequency range. For rectangular beams, it is suggested that a better expression should be proposed to fit the experimental results.